Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 60564b58de0777864e9696f38cf32354518d208c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
// SPDX-License-Identifier: GPL-2.0-only
/*
 * kernel/power/suspend_test.c - Suspend to RAM and standby test facility.
 *
 * Copyright (c) 2009 Pavel Machek <pavel@ucw.cz>
 */

#include <linux/init.h>
#include <linux/rtc.h>

#include "power.h"

/*
 * We test the system suspend code by setting an RTC wakealarm a short
 * time in the future, then suspending.  Suspending the devices won't
 * normally take long ... some systems only need a few milliseconds.
 *
 * The time it takes is system-specific though, so when we test this
 * during system bootup we allow a LOT of time.
 */
#define TEST_SUSPEND_SECONDS	10

static unsigned long suspend_test_start_time;
static u32 test_repeat_count_max = 1;
static u32 test_repeat_count_current;

void suspend_test_start(void)
{
	/* FIXME Use better timebase than "jiffies", ideally a clocksource.
	 * What we want is a hardware counter that will work correctly even
	 * during the irqs-are-off stages of the suspend/resume cycle...
	 */
	suspend_test_start_time = jiffies;
}

void suspend_test_finish(const char *label)
{
	long nj = jiffies - suspend_test_start_time;
	unsigned msec;

	msec = jiffies_to_msecs(abs(nj));
	pr_info("PM: %s took %d.%03d seconds\n", label,
			msec / 1000, msec % 1000);

	/* Warning on suspend means the RTC alarm period needs to be
	 * larger -- the system was sooo slooowwww to suspend that the
	 * alarm (should have) fired before the system went to sleep!
	 *
	 * Warning on either suspend or resume also means the system
	 * has some performance issues.  The stack dump of a WARN_ON
	 * is more likely to get the right attention than a printk...
	 */
	WARN(msec > (TEST_SUSPEND_SECONDS * 1000),
	     "Component: %s, time: %u\n", label, msec);
}

/*
 * To test system suspend, we need a hands-off mechanism to resume the
 * system.  RTCs wake alarms are a common self-contained mechanism.
 */

static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
{
	static char err_readtime[] __initdata =
		KERN_ERR "PM: can't read %s time, err %d\n";
	static char err_wakealarm [] __initdata =
		KERN_ERR "PM: can't set %s wakealarm, err %d\n";
	static char err_suspend[] __initdata =
		KERN_ERR "PM: suspend test failed, error %d\n";
	static char info_test[] __initdata =
		KERN_INFO "PM: test RTC wakeup from '%s' suspend\n";

	unsigned long		now;
	struct rtc_wkalrm	alm;
	int			status;

	/* this may fail if the RTC hasn't been initialized */
repeat:
	status = rtc_read_time(rtc, &alm.time);
	if (status < 0) {
		printk(err_readtime, dev_name(&rtc->dev), status);
		return;
	}
	rtc_tm_to_time(&alm.time, &now);

	memset(&alm, 0, sizeof alm);
	rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time);
	alm.enabled = true;

	status = rtc_set_alarm(rtc, &alm);
	if (status < 0) {
		printk(err_wakealarm, dev_name(&rtc->dev), status);
		return;
	}

	if (state == PM_SUSPEND_MEM) {
		printk(info_test, pm_states[state]);
		status = pm_suspend(state);
		if (status == -ENODEV)
			state = PM_SUSPEND_STANDBY;
	}
	if (state == PM_SUSPEND_STANDBY) {
		printk(info_test, pm_states[state]);
		status = pm_suspend(state);
		if (status < 0)
			state = PM_SUSPEND_TO_IDLE;
	}
	if (state == PM_SUSPEND_TO_IDLE) {
		printk(info_test, pm_states[state]);
		status = pm_suspend(state);
	}

	if (status < 0)
		printk(err_suspend, status);

	test_repeat_count_current++;
	if (test_repeat_count_current < test_repeat_count_max)
		goto repeat;

	/* Some platforms can't detect that the alarm triggered the
	 * wakeup, or (accordingly) disable it after it afterwards.
	 * It's supposed to give oneshot behavior; cope.
	 */
	alm.enabled = false;
	rtc_set_alarm(rtc, &alm);
}

static int __init has_wakealarm(struct device *dev, const void *data)
{
	struct rtc_device *candidate = to_rtc_device(dev);

	if (!candidate->ops->set_alarm)
		return 0;
	if (!device_may_wakeup(candidate->dev.parent))
		return 0;

	return 1;
}

/*
 * Kernel options like "test_suspend=mem" force suspend/resume sanity tests
 * at startup time.  They're normally disabled, for faster boot and because
 * we can't know which states really work on this particular system.
 */
static const char *test_state_label __initdata;

static char warn_bad_state[] __initdata =
	KERN_WARNING "PM: can't test '%s' suspend state\n";

static int __init setup_test_suspend(char *value)
{
	int i;
	char *repeat;
	char *suspend_type;

	/* example : "=mem[,N]" ==> "mem[,N]" */
	value++;
	suspend_type = strsep(&value, ",");
	if (!suspend_type)
		return 0;

	repeat = strsep(&value, ",");
	if (repeat) {
		if (kstrtou32(repeat, 0, &test_repeat_count_max))
			return 0;
	}

	for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
		if (!strcmp(pm_labels[i], suspend_type)) {
			test_state_label = pm_labels[i];
			return 0;
		}

	printk(warn_bad_state, suspend_type);
	return 0;
}
__setup("test_suspend", setup_test_suspend);

static int __init test_suspend(void)
{
	static char		warn_no_rtc[] __initdata =
		KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n";

	struct rtc_device	*rtc = NULL;
	struct device		*dev;
	suspend_state_t test_state;

	/* PM is initialized by now; is that state testable? */
	if (!test_state_label)
		return 0;

	for (test_state = PM_SUSPEND_MIN; test_state < PM_SUSPEND_MAX; test_state++) {
		const char *state_label = pm_states[test_state];

		if (state_label && !strcmp(test_state_label, state_label))
			break;
	}
	if (test_state == PM_SUSPEND_MAX) {
		printk(warn_bad_state, test_state_label);
		return 0;
	}

	/* RTCs have initialized by now too ... can we use one? */
	dev = class_find_device(rtc_class, NULL, NULL, has_wakealarm);
	if (dev) {
		rtc = rtc_class_open(dev_name(dev));
		put_device(dev);
	}
	if (!rtc) {
		printk(warn_no_rtc);
		return 0;
	}

	/* go for it */
	test_wakealarm(rtc, test_state);
	rtc_class_close(rtc);
	return 0;
}
late_initcall(test_suspend);